The present invention generically refers to the RF signals transmitting, for example to the systems used during transmitting and/or receiving radio-microphone signals.
More in particular, the invention concerns a typical installation used in the systems of receiving-transmitting, where more transmitting bases (each approved for a maximum power output, in relation to current regulation in the Country of approval) are “summed” with each other for being connected to a sole transmitting antenna, thus simplifying the installation of the system; this occurs by means of a device which is generally called adder or combiner, which may be realized by various design techniques, each of which has drawbacks and/or limits, limits which the following invention is meant to remove.
The approving regulations in the different countries limit the output level of the transmitters, limiting the maximum power at the output radio frequency, with possibly varying limits in the different frequency bands.
The manufacturers of the transmitters typically realize such devices starting from only one hardware design, limiting then the performance of the same by implementation of firmware/software (for example, loading configuration files), which are inserted in the control firmware/software of the apparatus, so that the final performance complies to the regulations of the Country where the apparatus is sold.
The total performance of the system is thus influenced by the combiner device; in particular if this is passive, in such case, as it is known, a part of the power is dissipated in the internal circuits, making only a fraction of the power from the transmitter available for the antenna.
As an alternative, combining devices with amplification stages inside, which retrieve the loss of the adder circuit, are commonly realized, but even this solution has remarkable drawbacks.